1. Field of the Invention
The present invention relates to a magnetic recording medium, esp., a magnetic recording medium used for recording video signals in direct recording systems by the low-range conversion of the chrominance signal components such as S-VHS format, and a method for making such a recording medium.
2. Prior Art
A video signal comprises a chrominance signal component and a luminance signal component. Applied to the domestic VCR standards for VHS, etc. are direct recording systems by the low-range conversion of the chrominance signals in which they are converted into low frequency.
A coated type of video tape used for such home VCRs has been increasingly advanced in performance by the micronization of magnetic powders and improvements in the surface properties of a magnetic layer.
Thus, the micronization of magnetic powders and the improvements in the surface properties of magnetic layers increase high-range output and reduce noise, improving the luminance signal S/N. The improvements in the surface properties of a magnetic layer also serve to improve the chrominance signal S/N.
Such improvements of video tapes have resulted in the advent of the S-VHS standards in 1987.
According to the S-VHS standards now established, the recording frequency of the luminance signal preset is so high that its characteristics can be improved increasingly.
In the video tapes for S-VHS which are designed to record very-high-frequency luminance signals, the magnetic powders are further micronized to achieve much more increased coercivity than before.
However, it is known in the art that the finer the magnetic powders and the higher the coercivity, the more improved the high-range characteristics, i.e., the luminance signal S/N but the worse the low-range characteristics, i.e., the chrominance signal S/N. Moreover, the S-VHS format makes a much larger difference in the recording frequency between the luminance and chrominance signals, since it is substantially similar to the VHS format in the recording frequency of the chrominance signal.
With the video tapes for the S-VHS format, it is thus difficult to obtain satisfactory S/N for both the luminance and chrominance signals.
Another problem with the conventional video tapes is that their durability, esp., their still life becomes insufficient or is lowered, because the finer the magnetic powders, the lower the mechanical strength of the magnetic layers.
The present invention, accomplished with such situations in mind, has for its object to provide a magnetic recording medium excelling in both the luminance signal S/N and the chrominance S/N and improved in durability, and a method for making it.